From patchwork Tue Oct 27 13:48:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 312777 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C418C55178 for ; Tue, 27 Oct 2020 14:56:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D41DD22284 for ; Tue, 27 Oct 2020 14:56:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810591; bh=5K4mB24GEmt7llTBmAUxj2Pvwn1GRGpPH2zA/89wIcI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VYRNAcPuBIlKcKhZLivz4svYDynD764B2jfpt6czsTee1GYybbA6/g5E56s1AvHwk c6zS5e8hZkBh061ZCEKWAUwZUP1HjpHNFHMypopIt5jREB3fFW+VhlvWmP8fSrWXSe rrW7qPIBZVE8f3hGWsZ3djkkYpaGn+b19ugN5SLo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1781961AbgJ0O4a (ORCPT ); Tue, 27 Oct 2020 10:56:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:57152 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1782043AbgJ0O43 (ORCPT ); Tue, 27 Oct 2020 10:56:29 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7680F2071A; Tue, 27 Oct 2020 14:56:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810589; bh=5K4mB24GEmt7llTBmAUxj2Pvwn1GRGpPH2zA/89wIcI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l5j+Pn1D7AY1HHjtbWNIrUZcc4iQMoHdjEEfiP2QNhPSbaqPbt6FG/zMeeO5/pg7M lTyLBXL3B/frJzj84Dqhv6mTcJUkBtVbj7q7xRSiWOyojQJkT9UxhNHZx+lfddLtel jltuQg0G7J143dSCa/d9MzwvvHZHMXEYKfHG6S60= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+e113a0b970b7b3f394ba@syzkaller.appspotmail.com, Christian Brauner , Todd Kjos , Jann Horn , Sasha Levin Subject: [PATCH 5.8 193/633] binder: Remove bogus warning on failed same-process transaction Date: Tue, 27 Oct 2020 14:48:56 +0100 Message-Id: <20201027135531.729146503@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135522.655719020@linuxfoundation.org> References: <20201027135522.655719020@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jann Horn [ Upstream commit e8b8ae7ce32e17a5c29f0289e9e2a39c7dcaa1b8 ] While binder transactions with the same binder_proc as sender and recipient are forbidden, transactions with the same task_struct as sender and recipient are possible (even though currently there is a weird check in binder_transaction() that rejects them in the target==0 case). Therefore, task_struct identities can't be used to distinguish whether the caller is running in the context of the sender or the recipient. Since I see no easy way to make this WARN_ON() useful and correct, let's just remove it. Fixes: 44d8047f1d87 ("binder: use standard functions to allocate fds") Reported-by: syzbot+e113a0b970b7b3f394ba@syzkaller.appspotmail.com Acked-by: Christian Brauner Acked-by: Todd Kjos Signed-off-by: Jann Horn Link: https://lore.kernel.org/r/20200806165359.2381483-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/android/binder.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index af85d37aef680..adab46ca5dff7 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2324,8 +2324,6 @@ static void binder_transaction_buffer_release(struct binder_proc *proc, * file is done when the transaction is torn * down. */ - WARN_ON(failed_at && - proc->tsk == current->group_leader); } break; case BINDER_TYPE_PTR: /*